Dump truck mechanism



24, 1940. LS. wool: 2,225,213

DUMP TRUCK MECHANI SM Filed Dec. 26, 1939 v s Sheets-Sheet 2 INVENTOR E 4 JallZ J 5 WZ 74 TTORNEIQ' p L s. woos 2,226,213

DUMP TRUCK MECHANISM Fired Dec. 26, 19:59 3 Sheets-Sheet :s

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Patented Dec.24,1940 i. v 2,226,213

UNITED STATES PATENTOFFICE DUMP TRUCK MECHANISM Louis S. Wood, Grosse Pointe Farms, Mich., as-

'signor to .Gar Wood Industries, Inc., Detroit, Mich., a corporation of Michigan Application December-'26, 1939, Serial No. 311,059 Claims. (01. 298-22).

The invention relates to an hydraulic hoist for Before explaining in detail the present invenuse on dump trucks to cause tilting of the truck tion, it is to'be understood that the invention is body about one end or side. More particularly, not limited in its application to the details of the invention relates to an hydraulic hoist of the construction and arrangement of parts illustype described having means connected thereto trated in the accompanying drawings, since the 5 and to the body and chassis capable of improving invention is capable of other embodiments and the action of the'hoist in various ways. of being practiced or carried out in various ways.

One of the primary objects of the present in- Also, it is to be understood that the phraseology vention is to provide an improved connection beor terminology employed herein' is for the purpose tween the tiltable truck body and the hydraulic of description and not of limitation, and it is not 10 power means so that the lifting force is most efintended to limit the invention claimed herein fective from a power standpoint at the the initial beyond the requirements of the prior art. stages of the lift, when the load is heaviest, and In the embodiment of the inventionv shown in by which the hoisting or lifting rate is increased the drawings, the numeral l0 represents a dump at the latter stages of hoisting, when the load has I truck of more or less conventional construction 15 been decreased. having a chassis H and a drivers cab I2 and A further object of the invention is to provide body l3 supported thereon. The body I3 has an improved connector mechanism of the type longitudinally. extending body members I, each mentioned which includes a lost motion linkage of which is provided on its rear end with a de- 0 connection so that in effect the power is applied pending bracket IS. The chassis Ii is provided directly against the body at the initial stages of with longitudinally extending sill members l6 lifting and thereafter is applied through a movwhich underlie the members M. 'The members l6 able linkage member at the latter stages of the have rearwardly extending plate members IUI hoisting, due to the action of the lost motion welded thereto; and the brackets l5 are pivotally linkage connection. connected to such plates by suitable pivot pins '25 Still further objects and advantages of the I02. The members I 4 are arranged to rest upon present invention will appear from the following the upper portions of Sills When the y l3 description and appended claims when considered is in its lowermost position. The body I3 is proin connection with the accompanying drawings in vided with transversely extending bracing memwhich: w hers I! which are welded to the members M at 30 Figure 1 is a side view of a dumptruck or spaced intervals therealong. Transversely exlike vehicle showing in dotted linesthe hydraulic tending members l8 are welded to the members hoist and associated mechanism constituting the i at Sp c intervals therealflng to ce the present invention; same.

5 Fig. 2 is a view in perspective showing one end In'order to raise n lower e ody abo t the of the truck with its body raised and clearly pivots I02, an hydraulic hoisting device, genershowing the hydraulic device used in accordance ally indicated at 20. is provided. Such hoisting with the present invention to accomplish this; device 20 comprises a cylinder 2| having a ta- Fig. 3 is a side view partly in section of the rear pered end cap 22 atits upper or rearwardly pro- 4o portion of the truck showing the position assumed jecting end, and a pair of hollow supporting and by the hydraulic hoisting means, when the body reinforcing wings 23 and 24 extending sidewardly of the truck is in its lowermost position; of the cylinder and longitudinally thereof which- Fig. 4 is a side view partly in section similar to are" in communication with the cylinder through Fig. 3, but showing in dot and dash lines the posithe front ends thereof. Bearing members 2511 tion of the hoisting means when the body is are fixed to the corners of wings 23 and 24 and 45 raised to an -intermediate position, and in full ve to pivotally receive the inner ends of stub lines the position of the hoisting means when the shafts l9. Such stub shafts have their outer body is in a substantially fully raised position; ends journaled in bearings I04 which are fixed Fig. 5 is a sectional view taken on the line 55 to the facing walls 25 and 26 of the sill members of Fig. 3, looking in the direction of the arrows; IS. A piston 21, having a piston rod 28 extend-' 50 Fig. 6 is 'a sectional view taken on the line 66 ing through the end cap 22, is reciprocably reof Fig. 3, looking in the direction of the arrows; ceived within the cylinder 2|. A packing element and 29 may be disposed within the opening through. Fig. 7 is a sectional view taken on the line 'I'| the cap 22 in surrounding relation to the rod 28 of Fig. 3, looking in the direction of the arrows. in the usual way. 55

A coil spring 32 is mounted within the end cap 22 and within the adjacent end of the cylinder 2| in surrounding relation to the piston rod 28. The rear end of the spring 32 is seated within and fixed to an inner annular groove formed in the end of the cap 22. The spring 32 serves as a bumper or cushion against which the piston 21 abuts as it approaches the end of its travel.

A plate or bracket member 33 is fixed to the under surface of each of the wings 23 and 24 and serves as a mounting for a gear pump 34. Such gear pump may be fixed to either of the plates 33 depending upon which side of the vehicle the pump will be most conveniently accommodated. The gear pump 34 is of conventional construction and is intended to be drive by means of a flexible shaft 35 which is connected to the take-off box 38 of the vehicle transmission in the usual way. The pump 34 may be controlled from the drivers cab by means of an operating lever 31, which is connectedto a control lever 38 on the pump through a cable 38. The control lever 38 is illustrated in Fig. 3 as being in, a neutral or non-operative position, while in Fig. 4 it is shown in its operative position, at which time the pump 34 is actuated to force fluid under pressure through a pipe or conduit 48 into the lower end of cylinder 2 I. This results in the upward movement of the piston 21 which causes dumping of the body |3 through a connection which will be hereinafter described in detail. Movement of the lever 38 to the other side of its neutral position results in a reversing action, and causes a lowering of the body.

The structure so far described per se forms no part of the present invention, but according to the present invention a novel connection between the piston rod 28 and the body [3 is provided whereby an improved lifting action results.

A leverage mechanism, generally indicated at 38, is p ovided for pivotally connecting the rod 28 to the body l3. This leverage mechanism includes a plurality of linkage members which are so disposed relative to each other and which are so connected to the chassis frame and to the body that at the initial stages of hoisting, the forces in effect are applied directly against the under surface of the body by the piston rod. Certain of the linkage members, which have lost motion connections with the other linkage member, come into action to effect an action of the latter mentioned linkage member which serves a lever to accelerate the rate of hoisting.

The leverage mechanism 38 thus comprises an upper linkage member 44 which is preferably formed of sheet metal. The member 44 is generally U-shaped in cross-section and has an upper wall 41, side walls 48 and 49, and .an end. plate 48a. The side walls 48 and 49 are generally triangular in shape having the greatest depth toward the rear end thereof. The ends of the pivot rod 4| project beyond the sides 48 and 49 and are trunnionei within bearings formed in longitudinally extending plate members 42. Such plate members 42 are welded to the-facing sides of the longitudinal beam members adjacent the floor of the body. These members v42 are provided with aligned bearing openings therein which receive the ends of a pivot rod 4| and thus pivotally mount the leverage member 44 with respect to the body I3.

The leverage mechanism 38 also includes lower linkage members, one of such linkage members being disposed at each side of the leverage member 44 at each side of the cylinder 2|. The lower or forward ends of the members 45 are pivotally connected to the stub shafts IS on the outside of cylinder 2|. I Such linkage members extend alongside of the cylinder 2| beyond the end of cap 22. U-shaped members 58 and 51 are welded to the inner faces of members 45 and form slotted integral extensions thereof, such slots being indicated at 88.

A pivot shaft 48 extends transversely of the member 44 and passes thrbugh openings in the side walls thereof adjacent the rear end thereof. Such pivot shaft also passes through openings in reinforcing plates 52 which extend longitudinally of the member 44 and which are welded to the base thereof in parallel relation to each other and to the sidewalls of member 44. The outer ends of the shaft 48 project beyond the sides of the walls 48 and 48 and pass through the slots 88 formed by members 58 and 51. Washers may be mounted on the outer ends of the shaft 48 and be fixed in position relative to the shaft by cotter keys, so that the shaft 48 is slidably and pivotally connected to the members 45 through the slots. A chain 58 has one end thereof connected to the shaft 48 and the other end thereof connected to one of the cross braces IT on the body I3 so as to limit the movement of the lever arm 44 as the body is raised.

The piston rod 28 is connected to the leverage member 44 by means of apivot shaft 58 which is mounted within aligned openings in the reinforcing plate members 52 and 53 and the side walls 48 and 49. Such shaft may be fixed in position by washers and cotter keys on the outer ends thereof. A T connection is suitably secured to the outer end of shaft 28, and the shaft 58 passes through the transverse opening in this connection so that the piston rod 28 is pivotally mounted with respect to the leverage arm 44.

When the body It is in ts lowermost position, the top wall 4'! of the leverage element 44 is in a position beneath and in contact with the floor 58 of the body, as shown in Fig. 3. At this time, the shaft 48 is in its lowermost position and is in a position rearwardly of and beneath the center lines of pivot shafts 4| and 58. The pivot shaft 48 is also at the forwardmost ends of slots 88 in members 45. The members 45 are of such a length with respect to the length of member 44, and in the embodiment illustrated is longer than the member 44, so that upon. actuation of the piston 2'|, the piston rod 28 effects a raising of the body l3 by direct application of force against the body at the point of the pivot shaft 58. This continues until the body has been raised a predetermined distance when upon further movement the shaft 48 slides within the slots 58 toward the rear ends thereof. When the shaft 48 reaches the ends of the slots 88, further raising of the body pulls the leverage member 44 away from the floor 58 ofthe body l3, so that the body is caused to pivot about the pivots I82 with the force applied to the body at the point of the shaft 4|. This causes an acceleration in the rate of dumping from the point at which the shaft 48 abuts against the ends of slots 88, and it will be seen that at this point the load has been partially dumped and that the greatest lifting effort is required at the initial stages of lifting.

Upon reversing the pump, the action of the leverage arms is reversed, with the result that the body descends most quickly at the beginning of its downward operation until the lever arm 44 again lies against the under surface of floor 58 when the body is lowered at a decelerated rate.

- truck, comprising,

To prevent damage of the floor 59 of the body as it contacts the upper wall 48 of the leverage element 44, a transversely extending angled brace BI is fixed on the rear end of member 44 in such a position as to contact one of the cross braces I'I. 'Thus, the brace Bl takes a substantial part of the jar as the member 44 abuts against the floor 59. Formal changes may be rnade in the specific embodiment of the invention described without departing from the spirit and substance of the invention, the scope of which is commensurate with the appended claims.

What is claimed is:

1. Apparatus for tilting the body of a dump truck comprising, in combination, a truck chassis,

a body pivotally connected to said chassis, a-

hoisting device having one end pivotally connected to said chassis and including a reciprocable element, an elongated lever element having one end thereof pivotally connected to said body and pivotally connected to said reciprocable element intermediate the ends of said lever element, an elongated linkage member having one end thereof pivotally connected to the other end of said lever element through a lost motion connection and having'its other end pivotally connected to said chassis, said linkage member extending towards said lever element in the same direction as said reciprocable element, and means for reciprocating said reciprocable element to tilt said body with respect to said chassis.

2. Apparatus for tilting the body of a dump chassis, a body pivotally connected to said chassis, a hydraulic hoisting device including a cylinder, means pivotally connecting one end of said cylinder to said chassis, a reciprocable element operativeiy associated with said cylinder, 'an elongated lever element having one end thereof pivotally connected to said body, means pivotally connecting one end of said reciprocable element to said lever element intermediate the ends thereof, an elongated linkage element having one end thereof pivotally connected to said chassis through said first named means, the other end at said linkage member being pivotally, connected to the other end of said lever element, and means for reciprocating said reciprocable element to tilt said body with respect to said chassis.

3. Apparatus for tilting the body of a dump truck, comprising, in combination, a truck chassis, a body pivotally connected to said chassis, a hydraulic hoisting device including a cylinder, means pivotally connecting one end of said cylinder to said chassis, a reciprocable element operatively associated with said cylinder, an elongated lever element having one end thereof pivotally in combination, a truck end of said lever element through a lost motion 7 connection, and means for reciprocating said reciprocable element to tilt said body with respect to said chassis.

, 4. Apparatus for tilting the body of a dump truck, comprising, in combination, a truck chassis, a body pivotally connected to the rear end of said chassis, a hydraulic hoisting device including a cylinder, means pivotally connecting" said cylinder to said chassis, a reciprocable element operatively associated with said cylinder, an elongated lever element extending longitudinally of said body, means pivotally connecting the forward end of said lever element to said body. means pivotally connecting one endof said reciprocable element to said lever element intermediate the ends of said lever element, an elongated linkage extending longitudinally of saidchassis alongside of said cylindenand having the forward end thereof pivotally connected to said chassis by said first named means, the opposite end of said linkage member being pivotally connected to the rear end of. said lever element through a lost motion connection, and means for reciprocating said reciprocable element to tilt said body with respect to said chassis.

'5. Apparatus for tilting the body of a dump truck, comprising, in combination, a .truck chassis, a body pivotally connected to the rear 'end of said chassis, a hydraulic hoisting device in-,.

cluding a cylinder, means pivotally connecting said cylinder to said chassis, a reciprocable element operatively associated with said cylinder, an elongated lever element extending longitudinally of said body, means pivotally connecting the forward end of said lever element to said body, means pivotally connecting one end of said reciprocable element to said lever element intermediate the ends of said lever element, a pair of elongated linkage members disposed on opposite sides of said cylinder and extending therealong, said linkage members having the forward ends thereof pivotally connected to said chassis by said first named means, the opposite ends of said linkage members being pivotally connected to the rear end-of said lever element through lost motion connections, and means for' reciprocating said reciprocable element to tilt said body with respect to said chassis.

LOUIS S. WOOD. 

